SMALL INTESTINAL BACTERIAL OVERGROWTH (SIBO) BREATH TESTING
WHAT IS SIBO?
Small Intestinal Bacterial Overgrowth (SIBO) is defined as an excess of bacteria in the small intestine. Use of antibiotics, diminished gastric acid secretion, small intestinal dysmotility (including in patients with long standing diabetes or celiac disease), history of chronic diarrhea, chronic alcohol use, and anatomical abnormalities of the GI tract are some of the predisposing factors that may increase the likelihood of developing SIBO. Once present, it has been suggested that this imbalance of bacteria may induce an inflammatory response in the small intestinal mucosa which produces many of the symptoms associated with this condition. Studies have demonstrated reversal of mucosal damage after treatment for SIBO.
WHAT ARE THE SYMPTOMS OF SIBO?
The symptoms of SIBO are non-specific and include bloating, abdominal pain/ distension, diarrhea, flatulence, fatigue, weakness and weight loss. Malabsorption and nutrient deficiencies, including vitamin B12, may also be found in patients with SIBO. The severity of these symptoms varies from mild to severe and is likely influenced by the degree of overgrowth and extent of mucosal inflammation.
WHAT IS THE RELATIONSHIP BETWEEN SIBO AND IRRITABLE BOWEL SYNDROME (IBS)?
The symptoms of SIBO are often indistinguishable from those attributed to Irritable Bowel Syndrome (IBS). There is a great deal of interest in better understanding the relationship between IBS and SIBO. While there remains debate within the scientific community, some studies have demonstrated that a significantly higher percentage of patients who met the Rome I criteria for IBS also tested positive on SIBO breath testing as compared to healthy controls. It has been suggested that the disordered motility and chronic diarrhea which can occur in some patients with IBS may predispose to SIBO.
HOW IS SIBO TREATED?
Treatment of SIBO is aimed at reducing the bacterial overload, correcting the underlying cause, and providing nutritional support including supplementation of any vitamin or mineral deficiencies that may be necessary. Antibiotics remain the mainstay of therapy and have been demonstrated to be effective in restoring normal bacterial balance, reducing mucosal inflammation and eliminating associated symptoms. Strict adherence to dietary modifications can also be helpful. Medications should also be reviewed to make sure that they are not exacerbating the underlying condition or contributing to the development of symptoms.